Hydrogen Gas Falling onto a Dark Matter Clump?

Sky field around the newly discovered 'blob'. The left image shows an HST image of part of the GOODS field, centred on the position of this unusal object. The two bottom right images show the same field observed in the B (blue) and R (red) bands with the ESO/MPG 2.2-m telescope at La Silla. In none of these images is the blob visible. It does only appear in the image obtained with FORS1 on the VLT, when observed through a dedicated narrow-band filter that detects hydrogen atoms that are around 11.6 billion light-years away. The top right image shows contours of this narrow-band emission overlaid on the HST image. It represents the field of view shown by the square in the top middle image. The position of the 'blob' is now obvious.